RPZ: Root protection zone fence, chain link, with 2" diameter iron posts driven 24" into the ground, 6 to 8 feet on center max. spacing. Alternative material:
chain link fence panels set over concrete block-type footings, with the fence panels wired to steel pins pounded 24 inches into the ground at both ends of each panel.
RB: Root buffer consisting of wood chip mulch lain over existing soil as a 12 inch thick layer, overlain with 1 inch or greater plywood strapped together with metal plates. This root buffer or soil buffer should be placed over the entire width of the construction corridor between tree trunks and construction.
RP: Root pruning. Prune woody roots measuring greater than or equal to 1 inch diameter by carefully back-digging into the soil around each root using small hand tools until an area is reached where the root is undamaged. Cleanly cut through the root at right angle to the root growth direction, using professional grade pruning equipment and/or a Sawzall with wood pruning blade. Backfill around the cut root immediately (same day), and thoroughly irrigate the area to saturate the uppermost 24 inches of the soil profile.
BDRP: Back-dig root pruning: Hand-dig around the broken root, digging horizontally into the open soil root zone until a clean, unbroken, unshattered section of the root is visible. Proceed as per ‘root pruning’.
RCX: Root crown excavation. Retain an experienced ISA-Certified arborist to perform careful hand-digging using small trowels or other dull digging tools to uncover currently-buried buttress root flares. Digging shall occur between trunk edge and at least two (2) feet horizontal from trunk edge. The final soil elevation will be at a level such that the tree’s buttress roots visibly flare out from the vertical trunk.
TB: Trunk buffer consists of 20-40 wraps of orange plastic snow fencing to create a 2 inch thick buffer over the lowest 8 feet of tree trunk (usually takes at least an entire roll of orange fencing per each tree). Lay 2X4 wood boards vertically, side by side, around the entire circumference of the trunk. Secure buffer using duct tape (not wires).
F: Fertilization with slow-release Greenbelt 22-14-14 tree formula, as a soil injection application using a fertilizer injection gun. This brand and formulation is commonly used by reputable tree care companies in the Bay Area. Apply at label rate and injection hole spacing.
M: 4-inch thick layer of chipper truck type natural wood chips (example source: Lyngso Garden Supply, self pick-up). Do not use bark chips or shredded redwood bark.
W: Irrigate using various methods to be determined through discussion with General Contractor. Irrigation frequency and duration to be determined through discussion and/or per directions in this report. Native oak species typically require 1x/month irrigation, while other tree species tend to prefer 2x/month or 4x/month moderate to heavy irrigation during construction.
P: Pruning per specifications noted elsewhere. All pruning must be performed only under direct site supervision of an ISA Certified Arborist, or performed directly by an ISA Certified Arborist, and shall conform to all current ANSI A300 standards.
MON: A Project Arborist must be present to monitor specific work as noted for each tree.
12.0 Tree Location & Protection Fence Map Mark-up by the CTA
The CTA marked up the applicant’s grading and utility plan sheet C-1 as the background for the tree map markup.
The CTA added the following items to this sheet for reference purposes:
a. Tree tag numbers are noted in black numeric oversized type. Important Note: The numbers on the CTA’s map refer to new racetrack shaped professional grade aluminum tags affixed to the trees or on the fencing in front of each tree, by the CTA. They are affixed to the mainstem of each tree at between 4 and 6 feet above grade.
b. Tree plot dots are in some cases added as new, or blackened, for clarity. Most of the CTA’s survey trees were not plotted by the applicant’s civil surveyor.
c. Canopy driplines of most of the trees were drawn out by the CTA to approximate scale, using black clouding.
d. Red dashing indicates suggested chain link root protection zone (RPZ) fencing routes, drawn to approximate true scale to indicate optimal placement in terms of root protection and preservation for trees #41, 42, and #45.
e. Yellow highlight along the south boundary of the map (bottom edge of map markup) indicates the applicant’s proposed joint trench (JT) and grassy swale grading location.
f. Yellow highlighting along the driveway indicates the location suggested by the CTA for use of biaxial geogrid or triaxial geogrid as an underlayment that would be pinned down directly over the existing soil at grade, over which the class II baserock base section would be tamped down. This would raise the elevation of the driveway significantly. This is an item for further discussion, since use of robust versions of biaxial or triaxial geogrid can allow for reduction of baserock base section thickness by as much as 50%. The goal here is to avoid all excavation cuts below grade elevation, such that the root system of tree #42 can be retained as-is without damages from the applicant’s current proposed plan to excavate 12 inches below grade for baserock base installation and concrete banding installation.
g. Blue highlight indicates areas where 1x/week heavy irrigation would be helpful in increasing tree growth (vigor) by boosting soil moisture in the root zone to field capacity.
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Site Address: 14300 Lora Drive, Los Gatos, CA Version: 9/25/2020
13.0 Attached: Appraisal Worksheet by the CTA
This appraisal worksheet was prepared using the 10th edition of the Guide for Plant Appraisal, 2nd Printing (2019). The dollar values of each survey tree derived from these calculations are useful in helping determine the monetary fines for construction team violations of the Town of Los Gatos tree ordinance, and for other Town Staff purposes. For instance, if a tree is found by an ISA Certified Arborist (e.g. the Project Arborist, or the Contract Town Arborist) to be
“50% damaged” in terms of below and/or above-ground losses to structure and/or health (vigor), the fine assessed on the construction team might be calculated as 50% of the tree’s appraised dollar value.
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Tree Tag # Name (Initials) WCISA Speces Group Classification Booklet Page Health (Weighted 0.15) Structure (Weighted 0.70) Form (Weighted 0.15) Overall Condition Rating (OCR) "Weighted Method" Diameter Inches at 4.5 ft. Above Grade Functional Limitations External Limitations WCISA Species Group Number Trunk Square Inches for Replacement-Size Specimen of This Species Average SF Bay Area Cost of 24 Inch Box Tree (2019) (UTC) Unit Tree Cost per Sq Inch (M Divided by L) Trunk Area (TA) ((dia. x dia.) x 0.785) Basic Functional Replacement Cost (BFRC) = (OxN) Depreciated Functional Replacement Cost (DFRC) = PxGxIxJ Rounded-off Appraised Values
41 Pc 25 0.75 0.75 0.8 76% 5.2 80% 90% 2 2.24 $250.00 $111.61 21.23 $ 2,369 $ 1,292 $1,290
42 Pc 23 0.85 0.85 0.85 85% $7,200
43 Ar 3 0.55 0.55 0.65 57% 7 40% 90% 4 4.75 $250.00 $52.63 38.47 $ 2,024 $ 412 $410
44 Ar 3 0.6 0.55 0.75 59% 7 40% 90% 4 4.75 $250.00 $52.63 38.47 $ 2,024 $ 428 $430
45 Ss 34 0.75 0.7 0.75 72% 8 60% 90% 4 4.75 $250.00 $52.63 50.24 $ 2,644 $ 1,021 $1,020
46 Pc 23 0.75 0.75 0.8 76% $20,300